const cityReducer = (prevState={},action)=>{
    // console.log(action)
    // 接受老状态， 深copy 返回新状态
    let  {type,payload} = action
    switch(type){
        case "GET_City":
            return {...prevState,...{payload}}
        default:
            return prevState
    }

    // return prevState
}

export default cityReducer